1993 2.3 Auto to 5.0 Manual

I have a 1993 Mustang Convertible that I removed the 2.3 4 speed from and I bought a 1989 302 to install. Is there a difference between the parts from the 1989-93? Should I buy engine parts for an 89 or 93? All I have from the 89 is the block, crank and pistons, and I will be using GT40 p heads and intake from a 98 explorer. Does it matter or will I have to buy any adaptors?
 
  • Sponsors (?)


Welcome to the site!

There really is no difference in hard parts between 79-93 that I'm aware of, so things like an oil pan or engine mounts will all interchange.

Now in your case, as far as I'm aware, and I'm sure others will jump in and give their knowledge, is that you'll most likely have problems with exhaust manifold/header fitment with P heads. You'll also want an engine harness from a FI car, preferably a 93 as there are slight differences from year to year. I'm not 100% sure which years are 100% compatible, but I do know that there are some differences - one of note is the O2 sensor harness. I also know that some years, like your 93, have the air bag harness tied into the engine harness, so that's something to keep in mind as well. You'll also want the appropriate PCM unless you're going with an aftermarket FI system like the Holley Terminator X. But as far as strictly engine components, everything more or less stayed the same between 87-93 as far as I'm aware. Like I said, I'm sure someone with more knowledge will most likely be along soon and can give more/better information than I....

OH - and post some pics and maybe start a build thread! Everyone loves to see pics! :)
 
I have a 1993 Mustang Convertible that I removed the 2.3 4 speed from and I bought a 1989 302 to install. Is there a difference between the parts from the 1989-93? Should I buy engine parts for an 89 or 93? All I have from the 89 is the block, crank and pistons, and I will be using GT40 p heads and intake from a 98 explorer. Does it matter or will I have to buy any adapto

Welcome to the site!

There really is no difference in hard parts between 79-93 that I'm aware of, so things like an oil pan or engine mounts will all interchange.

Now in your case, as far as I'm aware, and I'm sure others will jump in and give their knowledge, is that you'll most likely have problems with exhaust manifold/header fitment with P heads. You'll also want an engine harness from a FI car, preferably a 93 as there are slight differences from year to year. I'm not 100% sure which years are 100% compatible, but I do know that there are some differences - one of note is the O2 sensor harness. I also know that some years, like your 93, have the air bag harness tied into the engine harness, so that's something to keep in mind as well. You'll also want the appropriate PCM unless you're going with an aftermarket FI system like the Holley Terminator X. But as far as strictly engine components, everything more or less stayed the same between 87-93 as far as I'm aware. Like I said, I'm sure someone with more knowledge will most likely be along soon and can give more/better information than I....

OH - and post some pics and maybe start a build thread! Everyone loves to see pics! :)
Thank you so much!! I'm a 16yo kid still in school so I'm on a fairly tight budget but I'll keep everyone updated!! I always appreciate the support since I am not super knowledgeable and experienced!!!
 
So I swapped my Coupe from a 4 banger to a V8. This is the best thing you can read this first then come back with any specific questions:


Here is a thread on a 4 to 8 swap in an '89:


Google search will turn up a lot as will the search function on here. Read up and then post up specific questions as this has been covered quite a bit. Good luck and welcome to the forum!
 
  • Like
Reactions: malikaimiller08
Not really much mechanically different between 87-93 engines and such. EVen the speed density 87-88 engines are the same and can be used.

WHat's different is the wiring, which is what you need to pay attention to. The engine harnesses are fairly unique, and there are some one-year only harness out there that must all match.

FOr a 1993, you'll want to focus on wiring from a late 92-1993 Mustang. This will be the best for plug and play. 1990 was unique. 1991-early'92 is unique and 92-93 is unique. FUel pump relay was under the hood in 1993, and pre-92 cars put it under the driver's seat, so unless you want to change body harnesses, you'll want the same year engine harness. WHat makes this difficult is more folks selling harness don't know their are differences, forget what year the harness came out of and sell it as an 87-93 harness. This is incorrect.

Then you'll want to make sure the ECU model (5-spd or AOD ECU) , trans type (5-spd or AOD) and o2 sensor jumper are matching correct in your wiring.
 
Do you have a plan for the car? You need to have a goal in mind like street, street with some kind of racing (drag or road race) or all out race.

COP is all around pretty nice and accels at high rpm and high compression but it’s expensive and it will definitely require a tune or aftermarket injection system if you go EFI. If you are going carbed then it will still require an ignition system capable of running that type of setup.
 
Last edited:
Depends on how complicated your build is, the stock ignition system is pretty robust and handles a lot of HP.

Do you have a plan for the car? You need to have a goal in mind like street, street with some kind of racing (drag or road race) or all out race.

COP is all around pretty nice and accels at high rpm and high compression but it’s expensive and it will definitely require a tune or aftermarket injection system if you go EFI. If you are going carbed then it will still require an ignition system capable of running that type of setup.
Hoping for street with some racing aspects. Any fairy budget friendly options?
 
There are some differences in piston design for 5.0 engines, HO 5.0 has 'eyebrows', non HO does not and P heads may have a issue with 'kissing' the pistons. Show a pic of the piston tops.
1000000119.webp
1000000118.webp
 
Couple things about your pistons (if they are all the same part number) and I’m going off of memory here so 99% sure of these:
1) Do not clean the top of your pistons off like that. They need to be smooth. Soak them and brush them clean.
2) They use metric rings.
3) They are forged slugs and I believe the reliefs will clear up to 2.08” intake valves.
4) These came in 87-early 92 blocks.
 
Are those the heads you are going to use? If so flip it over and there should be a part number like what was on the piston in the rocker arm area. Just curious what they are.
 
Are those the heads you are going to use? If so flip it over and there should be a part number like what was on the piston in the rocker arm area. Just curious what they are.
Ill let you know when I am home, I am making a trip to the machine shop soon, I will be having the heads and deck resurfaced, valve guides redone, seals replaced, valves lapped, and the engine and heads being washed and baked in the oven, anything else I should get done? I was quoted $400-500.
 
Couple things about your pistons (if they are all the same part number) and I’m going off of memory here so 99% sure of these:
1) Do not clean the top of your pistons off like that. They need to be smooth. Soak them and brush them clean.
2) They use metric rings.
3) They are forged slugs and I believe the reliefs will clear up to 2.08” intake valves.
4) These came in 87-early 92 blocks.
How do I tell the bore for piston rings?